/* * MEN 16Z127 GPIO driver * * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de) * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the Free * Software Foundation; version 2 of the License. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/io.h> #include <linux/err.h> #include <linux/mcb.h> #include <linux/bitops.h> #include <linux/gpio/driver.h> #define MEN_Z127_CTRL 0x00 #define MEN_Z127_PSR 0x04 #define MEN_Z127_IRQR 0x08 #define MEN_Z127_GPIODR 0x0c #define MEN_Z127_IER1 0x10 #define MEN_Z127_IER2 0x14 #define MEN_Z127_DBER 0x18 #define MEN_Z127_ODER 0x1C #define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80) #define MEN_Z127_DB_MIN_US 50 /* 16 bit compare register. Each bit represents 50us */ #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ (db <= MEN_Z127_DB_MAX_US)) struct men_z127_gpio { struct gpio_chip gc; void __iomem *reg_base; struct resource *mem; }; static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, unsigned debounce) { struct men_z127_gpio *priv = gpiochip_get_data(gc); struct device *dev = gc->parent; unsigned int rnd; u32 db_en, db_cnt; if (!MEN_Z127_DB_IN_RANGE(debounce)) { dev_err(dev, "debounce value %u out of range", debounce); return -EINVAL; } if (debounce > 0) { /* round up or down depending on MSB-1 */ rnd = fls(debounce) - 1; if (rnd && (debounce & BIT(rnd - 1))) debounce = round_up(debounce, MEN_Z127_DB_MIN_US); else debounce = round_down(debounce, MEN_Z127_DB_MIN_US); if (debounce > MEN_Z127_DB_MAX_US) debounce = MEN_Z127_DB_MAX_US; /* 50us per register unit */ debounce /= 50; } spin_lock(&gc->bgpio_lock); db_en = readl(priv->reg_base + MEN_Z127_DBER); if (debounce == 0) { db_en &= ~BIT(gpio); db_cnt = 0; } else { db_en |= BIT(gpio); db_cnt = debounce; } writel(db_en, priv->reg_base + MEN_Z127_DBER); writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); spin_unlock(&gc->bgpio_lock); return 0; } static int men_z127_set_single_ended(struct gpio_chip *gc, unsigned offset, enum pin_config_param param) { struct men_z127_gpio *priv = gpiochip_get_data(gc); u32 od_en; spin_lock(&gc->bgpio_lock); od_en = readl(priv->reg_base + MEN_Z127_ODER); if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN) od_en |= BIT(offset); else /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */ od_en &= ~BIT(offset); writel(od_en, priv->reg_base + MEN_Z127_ODER); spin_unlock(&gc->bgpio_lock); return 0; } static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, unsigned long config) { enum pin_config_param param = pinconf_to_config_param(config); switch (param) { case PIN_CONFIG_DRIVE_OPEN_DRAIN: case PIN_CONFIG_DRIVE_PUSH_PULL: return men_z127_set_single_ended(gc, offset, param); case PIN_CONFIG_INPUT_DEBOUNCE: return men_z127_debounce(gc, offset, pinconf_to_config_argument(config)); default: break; } return -ENOTSUPP; } static int men_z127_probe(struct mcb_device *mdev, const struct mcb_device_id *id) { struct men_z127_gpio *men_z127_gpio; struct device *dev = &mdev->dev; int ret; men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), GFP_KERNEL); if (!men_z127_gpio) return -ENOMEM; men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); if (IS_ERR(men_z127_gpio->mem)) { dev_err(dev, "failed to request device memory"); return PTR_ERR(men_z127_gpio->mem); } men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start, resource_size(men_z127_gpio->mem)); if (men_z127_gpio->reg_base == NULL) { ret = -ENXIO; goto err_release; } mcb_set_drvdata(mdev, men_z127_gpio); ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4, men_z127_gpio->reg_base + MEN_Z127_PSR, men_z127_gpio->reg_base + MEN_Z127_CTRL, NULL, men_z127_gpio->reg_base + MEN_Z127_GPIODR, NULL, 0); if (ret) goto err_unmap; men_z127_gpio->gc.set_config = men_z127_set_config; ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio); if (ret) { dev_err(dev, "failed to register MEN 16Z127 GPIO controller"); goto err_unmap; } dev_info(dev, "MEN 16Z127 GPIO driver registered"); return 0; err_unmap: iounmap(men_z127_gpio->reg_base); err_release: mcb_release_mem(men_z127_gpio->mem); return ret; } static void men_z127_remove(struct mcb_device *mdev) { struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev); gpiochip_remove(&men_z127_gpio->gc); iounmap(men_z127_gpio->reg_base); mcb_release_mem(men_z127_gpio->mem); } static const struct mcb_device_id men_z127_ids[] = { { .device = 0x7f }, { } }; MODULE_DEVICE_TABLE(mcb, men_z127_ids); static struct mcb_driver men_z127_driver = { .driver = { .name = "z127-gpio", }, .probe = men_z127_probe, .remove = men_z127_remove, .id_table = men_z127_ids, }; module_mcb_driver(men_z127_driver); MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); MODULE_DESCRIPTION("MEN 16z127 GPIO Controller"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("mcb:16z127");